The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it may be described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present technology.
Battery performance can be improved by formation of a protective coating on the anode. Such as protective coating can prevent short circuits, thereby improving battery stability and extending the effective lifetime of the battery. In many instances, such protective coatings are formed during cell cycling, such as a solid electrolyte interphase (SEI) in which components of electrolyte and anode combine at the anode surface to form a protective coating on the anode. However, because ionic conductivity in an SEI is essential, SEI formation can limit certain electrolyte/anode combinations. Also, because SEI's are conventionally formed in situ, during cell operation, verification of an adequate protective coating can be uncertain.
Three-dimensional battery architectures, in which cathode surrounds anode in all directions, and/or impregnates a porous cathode, can eliminate “dead space” from a cell and improve energy density and power density. However, these architectures tend, by design, to place cathode and anode in very close proximity, sometimes in intricate and morphologically heterogeneous ways, as in the example of a cathode material impregnated into pores of a heterogeneously porous anode. In such applications, it may be desirable to form a reliable protective coating of known ionic conductivity on the anode prior to cell assembly. Accordingly, it would be desirable to develop pre-formed protective coatings for 3-D magnesium anodes, and methods for preparing them.